The invention relates generally to transport refrigeration systems and, more particularly, to an air exchange valve of a transport refrigeration system.
A transport refrigeration system is used to control an environment in an enclosed area, such as the insulated box on trailers, trucks, containers. The refrigeration system absorbs heat from the enclosed area and releases the heat outside of the box into the environment. Perishable items that are commonly transported in such refrigeration systems respirate over time, converting oxygen into carbon dioxide. If the concentration of oxygen is too low, or the concentration of carbon dioxide is too high, the cargo may be damaged. Fresh air exchanges avoid such a result by drawing fresh air into the system and forcing the carbon dioxide out an exhaust. The amount of fresh air drawn into the refrigeration system must be limited because the air may dry out the perishable items, and because power from the system must be used to cool the air.